package com.jafir.gps.util;

import com.amap.api.maps2d.model.LatLng;

/**
 * created by jafir on 2021-06-01
 */
public class ConvertUtil {
        private final static double a = 6378245.0;
        private final static double pi = 3.14159265358979324;
        private final static double ee = 0.00669342162296594323;

        // WGS-84 to GCJ-02  gps转高德
        public static LatLng toGCJ02Point(double latitude, double longitude) {
            LatLng dev = calDev(latitude, longitude);
            double retLat = latitude + dev.latitude;
            double retLon = longitude + dev.longitude;
            return new LatLng(retLat, retLon);
        }

        // GCJ-02 to WGS-84  高德转gps
        public static LatLng toWGS84Point(double latitude, double longitude) {
            LatLng dev = calDev(latitude, longitude);
            double retLat = latitude - dev.latitude;
            double retLon = longitude - dev.longitude;
            dev = calDev(retLat, retLon);
            retLat = latitude - dev.latitude;
            retLon = longitude - dev.longitude;
            return new LatLng(retLat, retLon);
        }

        private static LatLng calDev(double wgLat, double wgLon) {
            if (isOutOfChina(wgLat, wgLon)) {
                return new LatLng(0, 0);
            }
            double dLat = calLat(wgLon - 105.0, wgLat - 35.0);
            double dLon = calLon(wgLon - 105.0, wgLat - 35.0);
            double radLat = wgLat / 180.0 * pi;
            double magic = Math.sin(radLat);
            magic = 1 - ee * magic * magic;
            double sqrtMagic = Math.sqrt(magic);
            dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
            dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);
            return new LatLng(dLat, dLon);
        }

        private static boolean isOutOfChina(double lat, double lon) {
            if (lon < 72.004 || lon > 137.8347)
                return true;
            if (lat < 0.8293 || lat > 55.8271)
                return true;
            return false;
        }

        private static double calLat(double x, double y) {
            double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2
                    * Math.sqrt(Math.abs(x));
            ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;
            ret += (20.0 * Math.sin(y * pi) + 40.0 * Math.sin(y / 3.0 * pi)) * 2.0 / 3.0;
            ret += (160.0 * Math.sin(y / 12.0 * pi) + 320 * Math.sin(y * pi / 30.0)) * 2.0 / 3.0;
            return ret;
        }

        private static double calLon(double x, double y) {
            double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
            ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;
            ret += (20.0 * Math.sin(x * pi) + 40.0 * Math.sin(x / 3.0 * pi)) * 2.0 / 3.0;
            ret += (150.0 * Math.sin(x / 12.0 * pi) + 300.0 * Math.sin(x / 30.0 * pi)) * 2.0 / 3.0;
            return ret;
        }
 
}
